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  • 參數資料
    型號: SP6137EU
    英文描述: Wide Input, 900KHz Synchronous PWM Controller
    中文描述: 寬輸入,900kHz的同步PWM控制器
    文件頁數: 5/13頁
    文件大?。?/td> 142K
    代理商: SP6137EU
    5
    Date: 7/28/04 SP6137 Wide Input, 900KHz Synchronous PWM Controll Copyright 2004 Sipex Corporation
    tection features include thermal shutdown and
    short-circuit detection. In the event that either a
    thermal, short-circuit, or UVLO fault is de-
    tected, the SP6137 is forced into an idle state
    where the output drivers are held off for a finite
    period before a re-start is attempted.
    Under Voltage Lock Out (UVLO)
    The SP6137 contains two separate UVLO com-
    parators to monitor the bias (V
    CC
    ) and conver-
    sion (V
    IN
    ) voltages independently. The V
    CC
    UVLO threshold is internally set to 4.25V,
    whereas the V
    IN
    UVLO threshold is program-
    mable through the UVIN pin. When the UVIN
    pin is greater than 2.5V, the SP6137 is permitted
    to start up pending the removal of all other
    faults. Both the V
    CC
    and V
    IN
    UVLO compara-
    tors have been designed with hysteresis to pre-
    vent noise from resetting a fault.
    Soft Start
    “Soft Start” is achieved when a power converter
    ramps up the output voltage while controlling
    rent. In a modern step down converter, ramping
    up the positive terminal of the error amplifier
    controls soft start. As a result, excess source
    current can be defined as the current required to
    charge the output capacitor.
    IV
    IN
    = C
    OUT
    * DV
    OUT
    / DTSoft-start
    The SP6137 provides the user with the option to
    program the soft start rate by tying a capacitor
    from the SS pin to GND. The selection of this
    capacitor is based on the 10uA pull up current
    present at the SS pin and the 0.8V reference
    voltage. Therefore, the excess source can be
    redefined as:
    IV
    IN
    = C
    OUT
    * DV
    OUT
    *10
    μ
    A / (C
    SS
    * 0.8V)
    Hiccup
    Upon the detection of a power, thermal, or short-
    circuit fault, the SP6137 is forced into an idle
    state for 100mS (typical). The SS and COMP
    pins are immediately pulled low, and the gate
    drivers are held off for the duration of the
    timeout period. Power and thermal faults have
    to be removed before a restart may be attempted,
    whereas, a short-circuit fault is internally cleared
    shortly after the fault latch is set. Therefore, a
    restart attempt is guaranteed every 100mS (typi-
    cal) as long as the short-circuit condition per-
    sists.
    Thermal and Short-Circuit
    Protection
    Because the SP6137 is designed to drive large
    NFETs running at high current, there is a chance
    that either the controller or power converter will
    become too hot. Therefore, an internal thermal
    shutdown (145
    °
    C) has been included to prevent
    the IC from malfunctioning at extreme tempera-
    tures.
    A short-circuit detection comparator has also
    been included in the SP6137 to protect against
    the accidental short or sever build up of current
    at the output of the power converter. This com-
    parator constantly monitors the positive and
    negative terminals of the error amplifier, and if
    the V
    FB
    pin ever falls more than 250mV (typi-
    cal) below the positive reference, a short-circuit
    fault is set. Because the SS pin overrides the
    internal 0.8V reference during soft start, the
    SP6137 is capable of detecting short-circuit
    faults throughout the duration of soft start as
    well as in regular operation.
    Error Amplifier and Voltage Loop
    As stated before, the heart of the SP6137 voltage
    error loop is a high performance, wide band-
    width transconductance amplifier. Because of
    the amplifier’s current limited (+/-150
    μ
    A)
    transconductance, there are many ways to com-
    pensate the voltage loop or to control the COMP
    pin externally. If a simple, single pole, single
    THEORY OF OPERATION: Continued
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    相關代理商/技術參數
    參數描述
    SP6137EU/TR 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Wide Input, 900KHz Synchronous PWM Controller
    SP6137EU-L 功能描述:電壓模式 PWM 控制器 Wide Input, 900KHz Synchronous RoHS:否 制造商:Texas Instruments 輸出端數量:1 拓撲結構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
    SP6137EU-L/TR 功能描述:電壓模式 PWM 控制器 Wide Input, 900KHz Synchronous RoHS:否 制造商:Texas Instruments 輸出端數量:1 拓撲結構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
    SP6137HCU 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Dual Supply Synchronous Buck Controller
    SP6137HCU/TR 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Dual Supply Synchronous Buck Controller